Effect of Prostate Specific Membrane Antigen on Angiogenesis

Lee, Seung Tae; Lee, Young Goo; Park, Heung Won

Abstract

PURPOSE: PSMA (prostate specific membrane antigen) is a transmembrane glycoprotein, which is isolated from LNCaP. It is reported that PSMA is expressed in the vascular endothelium of various tumor. It has been suggested that PSMA can be related to angiogenesis. Herein, the effect of PSMA on angiogenesis was investigated with the HUVEC (human umbilical vein endothelial cell) line transfected with PSMA.
MATERIALS AND METHODS
mRNA was extracted from LNCaP. RT-PCR for PSMA ORF (open reading frame) was performed. PSMA ORF cDNA was subcloned into PcDNA 3.1(-) (BamH1 and Xba1 site) and transfection of PSMA on HUVEC was performed. HUVEC was plated onto a Matrigel coated 6 well plate and incubated at 37oC in a CO2 incubator for 18 hours. The HUVEC tube formation was observed every 2 hours using an inverted microscope. HUVEC cell protein was extracted immediately, and 3 and 6 hours after transfection. Western blot for VEGF (vascular endothelial growth factor) was performed.
RESULTS
The tube formation stage of HUVEC transfected with PSMA was observed 10 hours after incubation on Matrigel coating, whereas in the control HUVEC, the cord formation stage was observed after up to 10 hours incubation. The HUVEC transfected with PSMA showed an earlier tube formation stage than the control. Western blot analysis showed that PSMA transfection on HUVEC increased the expression of VEGF 2.5 fold in 3 hours and 1.89 fold in 6, as measured by densitometry.
CONCLUSIONS
PSMA transfection on the HUVEC cell line induced an initial increase in the expression of VEGF, and subsequently stimulated an earlier tube formation in the HUVEC cell line. These data suggest PSMA is related to angiogenesis.